Class 7 Science Chapter 2, Exploring Substances: Acidic, Basic, and Neutral, begins at a National Science Day fair where a sprayed liquid reveals hidden writing on white paper. It explains how natural indicators identify acidic, basic and neutral substances and how neutralisation works in daily life.
What Class 7 Science Chapter 2 Covers
2.1 Nature — Our Science Laboratory tests everyday substances using natural acid-base indicators: Litmus (blue and red litmus from lichens, 2.1.1), Red rose extract (2.1.2) and Turmeric paper/paste (2.1.3), plus olfactory indicators.
2.2 What Happens When Acidic Substances Mix with Basic Substances? demonstrates neutralisation reactions where an acid and a base react to form salt and water with the evolution of heat.
2.3 Neutralisation in Daily Life applies neutralisation to treating ant bites (formic acid with baking soda/calamine), indigestion, acidic or basic farm soil, and factory waste.
Exercises in Chapter 2
- In a Nutshell key points summary and Let Us Enhance Our Learning chapter exercises.
- Exploratory Projects and Dive Deeper hands-on science activities.
Read Class 7 Science Chapter 2 Online
More Chapters
- Previous: Chapter 1: The Ever-Evolving World of Science
- Next: Chapter 3: Electricity: Circuits and their Components
- Hindi medium: Class 7 Science Chapter 2 PDF in Hindi (Jigyasa)
- All Science chapters and the other Class 7 books: Class 7 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
FAQ
What colour does litmus turn in acids and bases?
Blue litmus turns red in acidic solutions, while red litmus turns blue in basic solutions; neutral solutions do not change the colour of either.
How do you treat an ant bite using neutralisation?
An ant sting injects acidic liquid (formic acid) into the skin, which can be neutralised by rubbing moist baking soda or calamine solution (mild bases).